1. Field of the Invention
The present invention relates to a telephone used in a telephone system for transmitting voice data transmitted from an authorized telephone with speech authority, to a plurality of unauthorized telephones without speech authority.
2. Related Background Art
The telephones proposed for simultaneous conversation among three or more persons include those enabling a bidirectional voice call among the telephones used by the three or more persons (Japanese Patent Application Laid-Open No. 2004-222194).